A tennis player seeking to improve his or her game may hire an instructor who observes the player and then informs him or her orally whether or not he or she has executed the serve or other forehand stroke or backhand stroke properly. The instructor may then show the player the correct way to execute the stroke. An advantage of this type of practice is that the player receives individual attention from the instructor during the time period that the instructor is with the player. On the other hand this mode of practicing can be quite expensive and must be scheduled in advance at a time when both the instructor and the player are available.
The art has developed a number of training devices that a player can use without an instructor at a time and place that is convenient to the player. Many of these training devices employ sensors on the tennis racquet to detect movement of the tennis racquet and ball strikes. For example U.S. Pat. No. 4,163,552 discloses an apparatus for facilitating the practice of tennis which has a housing that is attached to the neck of the tennis racquet. An elastic band is connected between the housing and a pole to limit movement of the tennis racquet during the swing and help define a path of travel. Sensors and bells are provided on the housing to indicate when the racquet reaches certain points in the path of travel.
U.S. Pat. No. 8,602,922 B2 discloses a method and apparatuses for enhancing performance in racquet sports. One or more sensors are provided on the tennis racquet. The sensor may be one or more accelerometers used to measure acceleration associated with racquet movement. An anemometer can be used to sense air speed relative to the racquet. A pressure sensor may be provided to measure tension on the strings or to measure the pressure exerted by the user on the handle while gripping the racquet. A strain gauge sensor may be provided to sense the strain applied to the strings or to sense the impact forces generated when a ball impacts against the strings. Piezoelectric sensors may be provided to identify locations where the ball strikes the racquet. A skin sensor may be provided on the grip to sense the player's heart rate. The sensors are connected to a processor on the racquet or remote from the racquet.
U.S. Pat. No. 5,757,266 discloses an electronic apparatus for providing player performance feedback in which sensors are provided on the racquet to indicate impact locations where a ball strikes the racquet.
While these devices can be helpful training aids, they can be expensive and require a power source. Furthermore, the sensors, bells and hardware used to attach them add weight to the tennis racquet and may change the center of gravity of the racquet. That weight is not present when the player plays a tennis match. Having added weight on the racquet makes the training conditions significantly different than the conditions that are encountered during play.
There is a need for a tennis training device that does not add much weight to the tennis racquet. This training device should be portable and more closely simulate playing conditions than the training devices that attach sensors to the tennis racquet.